It is conventional wisdom in the espresso industry that espresso grinders and their output of ground coffee should be cool to provide higher quality espresso beverages. It is common practice for espresso grinder manufacturers to install fans or other cooling devices in grinders for this purpose.
Historically, espresso grinders comprise a grinder and a doser assembly. A grinder is manually or automatically turned on to fill a doser to a predetermined level. In this way, an operator can then pull a lever to dose a certain amount of coffee into a portafilter, or group handle. Unfortunately, some ground coffee can sit in the doser for an extended period of time which in turn affects the freshness of the ground coffee as ground coffee loses its freshness much faster than whole coffee beans.
In an effort to solve this problem and ensure the coffee is ground fresh each time, manufacturers developed doserless grinders. Doserless grinders are purported to be accurate in terms of the dose of ground coffee they dispense. Doserless grinders often operate on a timed basis; hence 3-second activation would dispense less coffee than 4-second activation. Unfortunately, doserless grinder often provide inconsistent doses even when the variables of motor speed and grind size adjustment are consistent due to temperature differences in the grinder or in the beans within the grinder.